In 1921, Albert Einstein wrote a letter to the Berlin rabbis in which he observed, “I notice that the word Jew is ambiguous in that it refers (1) to nationality and origin, (2) to the faith.” Population genetics research is adding new meaning to Einstein’s view of being Jewish by showing that the history of the Jews can be seen in their genes. Jews can be said to be a people with a shared genetic legacy, but not all Jews share the same genes, nor is having part of that legacy a requirement for being Jewish. Nonetheless, shared genetic legacy can be a factor in Jewish identity that takes its place alongside those factors identified by Einstein — nationality (or group membership), the culture emanating from group membership and shared religious belief. Dr. Harry Ostrer, professor of pathology, genetics and pediatrics at Albert Einstein College of Medicine, and director of genetic and genomic testing at Montefiore Medical Center, leads a discussion of this fascinating topic. Co-sponsored by Hebrew College and the Jewish Genealogical Society of Greater Boston.